The objective of this study is to gain information concerning the biochemistry of certain acrosomal enzymes, their seminal plasma inhibitors, capacitation, and sperm-ovum fusion in the human. Sperm acrosin, hyaluronidase and "corona penetrating enzyme" are known to have an important role in the fertilization process and these enzymes will be purified and characterized from human spermatozoa. Particular emphasis will be placed on their active site and kinetic properties, and the reaction with specific synthetic inhibitors. The antifertility properties and physiological aspects of the most active inhibitors will be tested. The interaction of the enzymes with the naturally occurring antifertility agents: decapacitation factor and proteinase inhibitors, will be studied. These inhibitors will be purified and characterized from human seminal plasma. They will be cleaved to low Mw peptides that retain their antifertility and inhibitory activity; the peptides will be isolated and analyzed. The location of these enzymes and seminal plasma inhibitors on human spermatozoa will be evaluated as well as their role in the capacitation process. The layers surrounding the ovum will be studied biochemically and their interactions with acrosomal enzymes will be tested. The proposed studies will lead to a better understanding of the capacitation and fertilization process in man and increase our knowledge concerning spermatozoa and male genital tract secretions. Additionally the research is of practical value since the inhibition of acrosomal enzymes prevents fertilization. Increased knowledge of these enzymes and their inhibitory agents may therefore lead to the development of new contraceptive agents. BIBLIOGRAPHIC REFERENCES: Bhattacharyya, A.K. and Zaneveld, L.J.D. Evaluation of the substrate-film (gelatin plate) test for human acrosin. Second Annual Meeting, American Socity of Andrology, California, p. 3, 1977. Bhattacharyya, A.K. and Zaneveld, L.J.D. Acrosin release from human spermatozoa. Fed. Proc. 36:371, 1977.